All of the models still keep the heaviest snow bands well south & east of the Twin Cities with this system.

Until Tuesday PM, most of the models have kept most all the snow away from the metro.

But Tuesday the GFS showed a trend toward extending the northern edge of the snow shield a little further north…into the Twin Cities Wednesday night & Thursday AM.

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Image: NOAA GFS snowfall output via wxcaster.com

The oft (and appropriately) maligned GFS has been one of the better models with the past few systems coming through Minnesota.

The Euro model is now also indicating some (lighter) snowfall for the metro Wednesday night & Thursday.

Heres’ a look at the liquid moisture (QPF) laid out by the models.

GFS: .18″

Euro .10″ (2.7mm)

The totals are not that impressive, but with cold air around the snow:liquid ratios in Minnesota with this system could be quite high…maybe as high as 15:1 or even 25:1.

25:1 is like winning a long shot at the track.

Here’s what the paltry .18″ of liquid (the going GFS forecast) translates to as snowfall at various ratios.

15:1 = 2.7″

20:1 = 3.6″

25:1 = 4.5″

That could translate into some “shovelable” and even “plowable” snow and greasy roads for parts of the metro…especially the southeastern parts.

Image: Iowa State University

The Twin Cities NWS shows some interest in this trend in their Tuesday PM forecast discussion, especially for southeast Minnesota.

THIS STORM SYSTEM HAS MOVED INTO THE SW U.S. EARLIER TODAY…WITHSNOW ALREADY DEVELOPING IN THE CENTRAL ROCKIES. THE MAIN FORECASTCONCERN IS QPF AMTS WHICH COULD MEAN HIGHER SNOWFALL TOTALS IFHIGHER SNOWFALL RATIOS DEVELOP TO THE NW OF THE STORM SYSTEM. THIS MORNING SYSTEM HAD RATIOS OF 18-1 TO 25-1. EVEN WITH A CONSERVATIVE SNOWFALL RATIO OF 15-1 COULD PRODUCE 3.5 INCHES OF SNOWFALL WITH ONLY A QUARTER INCH OF LIQUID WATER. BASED ON THE LATEST MODELS HAVING AS MUCH AS 0.50 INCHES OF LIQUID WATER BY THU AFTN…THIS WOULD BE EQUAL TO 7.5″ OF SNOW.

If the GFS trend is right, the metro may see a period of light snow from around 6pm Wednesday evening to 6-9 am Thursday. Snowfall under this scenario could produce 1″ to 2″+ for parts of the metro…with 3″+ or more very close to… or possibly sneaking into parts of the metro.

About the blogger

Paul Huttner is chief meteorologist for Minnesota Public Radio. Huttner has worked TV and radio stations in Minneapolis, Tucson and Chicago. Paul is a graduate of Macalester College in St. Paul and holds a bachelor’s degree in geography with an emphasis in meteorology.